The present invention relates to a maintenance tool for a control system. More particularly, it relates to a control-system maintenance tool for ensuring the safety on management side by permitting only users who are authorized to edit a program to perform the program editing.
A method has been known in which a user himself or herself customizes the user interface of an application to give authentication to other users who are permitted to use the program-editing function (JP-A-7-110763 and JP-A-7-334213).
According to this method, the user himself or herself makes it possible to give authentication to other users properly. This feature makes it possible to give authentication to an operator who performs an operation that will yield serious influences on the control system. This authentication allows implementation of the ensuring of the safety on operation side. Also, it is prohibited to display a program to an unauthorized user to whom the authorization to edit this program is not granted whereas the program is displayed only to an authorized user to whom the authorization to edit this program is granted. This feature allows implementation of the ensuring of the safety on management side.